The invention is directed to a method for placing modules on a carrier upon employment of a module list containing the dimensions of the modules and of a network list containing the connections of the modules.
Methods for placing modules on a carrier, for example for placing gate arrays, standard cells, macro cells on a chip or for placing modules on printed circuit boards, are known. Let the following be referenced as examples of the prior art: Cheng, C. K., Kuh, E. S., Module Placement based on Resistive Network Optimization, IEEE Transactions on Computer-Aided Design, Vol. CAD-3, 1984, pages 218 through 225; Just, K. M., Kleinhans, J. M., Johannes, F. M., on the Relative Placement and the Transportation Problem for Standard-Cell Layout, Design Automation Conference, 1986, pages 308 through 313. These references recite methods with whose assistance modules are first placed on the carrier in their relative position with respect to one another and are then assigned their ultimate position on the carrier. The point of departure is the topology of the circuit, i.e., for example, a wiring diagram, from which how a plurality of modules are connected to one another derives. The job of the placement is to then optimally arrange these modules on a carrier, for example a chip, taking their connections into consideration. The placement method is described in detail in the said references, these being referenced herein.
The known methods first strive for a relative placement of the modules relative to one another. To that end, the coordinates of the individual modules are calculated such that the center of gravity of the modules is at a prescribed point, for example the center coordinate of the area of the placement surface provided for the arrangement. The coordinates of the modules are calculated by solving an optimization problem, whereby a function of the distances of the modules connected to one another is made into a minimum. The solution of this optimization problem ensues taking secondary conditions into consideration; what is thereby achieved is that the modules lie optimally uniformly distributed on the placement surface. The calculation of the ultimate and overlap-free position of the modules ensues after the end of the relative placement. The information of the relative placement is thereby used.